allow imports to empty dirs

synth/src/cli/mod.rs

@@ -137,9 +137,9 @@ impl Cli {
                 self.store.save_collection_path(&path, collection, content)?;
                 Ok(())
             }
-        } else if self.store.ns_exists(&path) {
+        } else if self.store.ns_exists(&path) && !self.store.ns_is_empty_dir(&path) {
             Err(anyhow!(
-                "The directory at `{}` already exists. Will not import into an existing directory.",
+                "The directory at `{}` already exists and is not empty. Will not import into an existing directory.",
                 path.display()
             ))
         } else {

synth/src/cli/store.rs

@@ -64,6 +64,11 @@ impl Store {
         self.ns_path(namespace).exists()
     }
 
+    pub fn ns_is_empty_dir(&self, namespace: &Path) -> bool {
+        self.ns_path(namespace).is_dir() 
+            && self.ns_path(namespace).read_dir().map(|mut dir| dir.next().is_none()).unwrap_or_default()
+    }
+
     pub fn collection_exists(&self, namespace: &Path, collection: &Name) -> bool {
         self.collection_path(namespace, collection).exists()
     }